patients, and i kept using them. and they'll pay for the same patient every time. >> kroft: once the crooked companies get hold of the patient lists, usually stolen from doctors' offices or hospitals, they begin running up all sorts of outlandish charges and submit them to medicare for payment, knowing full well that the agency is required by law to pay the claims within 15 to 30 days, and that it only has enough auditors to check a tiny fraction of the charges to see if they are legitimate. if they're not, it's usually people like 76-year-old clara mahoney who catch them. she began to notice all sorts of crazy things turning up on her quarterly medicare statements back in 2003, things that medicare paid for on her behalf and that she had never ordered, never wanted, and never received. what kind of things? >> clara mahoney: oh, air mattresses, a wheel chair, urine bag for my leg. ( laughs ) it was getting so i didn't want to open up the... the explanation of benefits because, you know, it's like, "oh, no, not again.